Align Technology Inc v. 3Shape AS

1. Case Identification

• Case #: IPR2021-01313
• Patent #: 10,905,333
• Filed: July 30, 2021
• Petitioner(s): Align Technology, Inc.
• Patent Owner(s): 3Shape A/S
• Challenged Claims: 1, 9-10, 15-17, 19, 21, 29-30, 33-35, and 37

2. Patent Overview

• Title: 3D Intraoral Scanner Measuring Fluorescence
• Brief Description: The ’333 patent is directed to an intraoral scanning system for detecting cariogenic regions on a tooth. The system uses two different light wavelengths: one to collect data for generating a 3D surface topography of the tooth, and a second to collect data corresponding to cariogenic regions for digital representation.

3. Grounds for Unpatentability

Ground 1: Claims 1, 9-10, 15-17, 19, 21, 29-30, 33-35, and 37 are obvious over Oota in view of Liang.

• Prior Art Relied Upon: Oota (Application # 2010/0253773) and Liang (Application # 2008/0063998).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Oota taught a 3D intraoral scanning system that used two light sources emitting different wavelengths to distinguish between dental regions (e.g., enamel, dentin) and create a 3D image. Oota’s system illuminated the tooth sequentially with the different wavelengths. Liang taught a method for detecting cariogenic regions specifically by using fluorescence, where different light wavelengths excite fluorescence to distinguish between healthy and demineralized enamel or to detect cariogenic bacteria. Petitioner contended that combining Oota’s base 3D scanning system with Liang’s specific method for caries detection met all limitations of the independent claims, including the use of first and second light sources for 3D topography and cariogenic region detection, respectively.
  • Motivation to Combine: A POSITA would combine these references to improve the functionality of Oota’s scanner. Oota disclosed that its optical principles could be used to detect various dental conditions and even recognized that "cariogenic conditions" cause differences in optical response. Liang provided a well-known fluorescence-based technique to do precisely that. Given the significant interest in improving caries detection, incorporating Liang’s established method into Oota’s advanced 3D scanning platform would have been a logical step to enhance its diagnostic capabilities.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success because both Oota and Liang described systems using similar components, such as light sources, image sensors, and processors, to analyze optical responses from a tooth. Integrating Liang’s fluorescence detection, which involves known techniques like using spectral filters, into Oota’s system, which already managed multiple wavelengths, was presented as a predictable and straightforward modification.

Ground 2: Claims 1, 15-17, 19, 21, 33-35, and 37 are obvious over Babayoff.

• Prior Art Relied Upon: Babayoff (Patent 7,698,068).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was argued under the Patent Owner’s broader claim construction that does not require fluorescence for detecting cariogenic regions. Petitioner asserted that Babayoff taught a 3D intraoral scanner that creates a colored digital 3D model of a patient's teeth by sequentially illuminating them with multiple light sources (e.g., blue, green, red) and mapping the captured color data onto the 3D surface. Petitioner argued that because it was well-known that color variations on teeth can indicate cariogenic regions, Babayoff's system, by capturing and displaying color data, inherently provided a "digital representation of the cariogenic region." Thus, Babayoff alone was alleged to teach all elements of the challenged claims.
  • Motivation to Combine (Anticipation-like argument): As this is a single-reference ground, the argument was that Babayoff taught the claimed invention. A POSITA would have immediately recognized that applying Babayoff’s color scanning system to detect caries was a straightforward and inherent application, as visual inspection of tooth color was a common method for caries assessment.

Ground 3: Claims 1, 15-17, 19, 21, 33-35, and 37 are obvious over Babayoff in view of Everett.

• Prior Art Relied Upon: Babayoff (Patent 7,698,068) and Everett (Patent 6,522,407).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground also relied on the broader, non-fluorescence claim construction. Babayoff provided the foundational 3D color intraoral scanning system. Everett taught an alternative optical method for detecting caries by illuminating a tooth with polarized light and measuring the degree of depolarization, which increases significantly when light reflects from carious regions. Petitioner argued that incorporating Everett's specific and quantitative caries detection method into Babayoff’s general-purpose 3D scanner rendered the claims obvious.
  • Motivation to Combine: A POSITA would combine Babayoff and Everett to improve the accuracy and sensitivity of caries detection over what is possible with color imaging alone. Everett’s method provided a quantitative measure of demineralization, offering a more robust diagnostic tool. Petitioner noted that Babayoff’s system already included polarizers in its optical path, which would make the integration of Everett’s depolarization measurement technique a simple and logical enhancement.
  • Expectation of Success: There was a high expectation of success because Babayoff's optical system was already well-suited for implementing Everett's teachings. The presence of polarizers in Babayoff meant that measuring depolarization could be achieved with minor, predictable adjustments, such as adding a beamsplitter or rotating an existing polarizer to analyze different polarization states.

4. Key Claim Construction Positions

• Petitioner highlighted key claim construction disputes from a related district court litigation, arguing the claims are unpatentable under either party's proposed construction.
• "cariogenic region of the tooth": Petitioner proposed a narrow construction requiring detection "from emitted fluorescence," based on the patent's specification. The Patent Owner argued for a broader plain and ordinary meaning not limited to fluorescence. Petitioner's primary arguments for Grounds 2 and 3 relied on the Patent Owner's broader construction.
• "a second light source": Similarly, Petitioner argued this term should be construed as "a light source used to excite a fluorescent material of a tooth," while the Patent Owner advocated for its plain and ordinary meaning.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §314(a) based on the Fintiv factors was unwarranted.
• The parallel district court litigation was argued to be in its very early stages, with no trial date set and discovery not yet commenced. Petitioner stated its intent to file a motion to stay the litigation pending the outcome of the inter partes review (IPR), weighing against denial.
• Petitioner further contended that the invalidity grounds presented in the petition differ from those in the parallel litigation and that the strength of the prior art strongly favored institution.

6. Relief Requested

• Petitioner requests institution of IPR and cancellation of claims 1, 9-10, 15-17, 19, 21, 29-30, 33-35, and 37 of the ’333 patent as unpatentable.